A Front-Mount for the 2015 STI, Part 3: Hot-Side Intercooler Pipe Fabrication

With our cold-side piping complete, it was time to focus on the hot side. This portion of the piping system would require a bit more attention, mainly because we were unable to scavenge any existing pipes from our WRX/STI front-mount intercooler kits (as we did with the cold side). Let’s get to it!

Piping Fabrication

The hot-side piping will route from the turbocharger compressor outlet, around the driver side of the engine bay, and into the front bumper area to attach to the intercooler.

Here is a look at the turbocharger connection point.

2015 STi front-mount intercooler hot-side pipe turbo connection

A coupler attaches the pipe to the turbocharger.

The end of this pipe must attach to our intercooler, which is mounted within the front bumper area. This requires snaking the piping through the engine bay and locating an ideal spot for the piping to travel outside of the engine compartment.

2015 STi Intercooler pipe connection

We should have no issues routing our pipe between the washer reservoir and the body.

Our team started fabrication at this location, which would likely be the most challenging portion of this pipe design process. We started making cuts on our piping and then mocking pieces into place.

2015 STI parts fabrication

The process that followed included making multiple cuts, some trial-and-error for fitment, and soon enough, our work behind the bumper was complete.

2015 STI parts fabrication

With the bumper fitting perfectly, we turned our attention to the piping within the engine bay.

2015 STI parts fabrication

Mating these two pipes became a bit tricky. The battery occupies a large portion of this side of the engine bay and occupies some of the space where we intended to locate our pipe. We could neck the pipe down slightly, but that could result in vibrational noise because clearance would be extremely tight between the pipe and battery.

We found an alternative solution!

2015 STi front-mount intercooler hose fabrication

We will be joining these two portions of the hot-side with a large silicone coupler. This will provide for an easy installation process and will eliminate the chance of noise from vibrations.

This mock-up unit is constructed from three different sections of existing couplers we have in our arsenal. The end product will be a one-piece component designed specifically for this kit.

2015 STi front-mount intercooler hose fabrication

This completed the fabrication phase of our hot-side pipe and coupler assemblies. As with the cold-side pipe, we needed to collect the dimensions from our fabricated prototypes to create 3D models of the features. All piping was tack-welded, and we used our CMM (coordinate measuring machine) to collect all dimensional data.

Coming Up – Final Test Fit and Discounted Pre-Sale

This project is moving along quickly! Within the next few weeks we will be completed with our set of functional prototypes for final product test fitting. Once we are sure everything fits perfectly, we will launch a discounted pre-sale for those interested in picking up a kit.